Air compressor



J. Q. CARREY March 16 1926.

AIR COMPRESSOR Filed August 8, 1922 s SheetS-Shet 1 fave/z far March 161926.

. J. O. CARREY AIR cournssson Filed August 1922 8 sheets-sum 2.ZFzaezziw- .L/0/ZZZ 0. 'arny March 16; 1926. 1,5765% J.O.CARREY AIRCOMPRESSOR March 16 1926. 1,576,571

J. o; cARREY AIR COMPRESSOR Filed August a, 1922 8 Sheets Shee't 5.Zizwrziar Ja/bz d 'arvgy March 16 1926.

J. O. CARREY AIR COMPRESSOR Filed August 8, 1922 8. Sheets-Shee't' 7nae/Zia) March 16 1925. 1,575,571

J. O. CARREY AIR COMPRESSOR I Filed August 8, 1922 a Sheets-Shea: a

I I I I I Patented Mar. 16, 1926.

UNITED STATES PATENT OFFICE.

JOHN O. GAR/REY, OF ST. LOUIS, MISSOURI, ASSIGNOR '10 CARREYeMORSEENGINEER- ING COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OFMISSOURI.

Air. COMPRESSOR.

Application filed August 8, .1922. Serial No. 580,386.

.7 '0 all whom it may concern:

Be it known that I, JOHN O. Gemini, a citizen of the United States,residing at St. Louis, Missouri, have invented a certain new and usefulInn'n'ovementin Air Compressors, of which. the following is a full,clear, and exac description, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, forming part of this application.

This invention relates to new and useful improvements in air compressorsand the principal objects of the invention are to generally improve uponand simplify the construction of air compressors and to increase theefiiciency thereof.

Other objects of the invention are to provide an air compressor. havinga speed va riable driving connection whereby the speed of the pistons isautomatically varied in accordance with the load during the compressionstroke of the device.

Further objects of the invention are to mount the crank pin in a blockslidably mounted in an angularly disposed slot formed in a floatingmember, the latter being arranged in a ring on which the primary pistonsare mounted so that during the last half of the compression stroke, thepressure exerted against-said floating member causes the latter to bepartially rotated, thus changing the angle of the slot and automaticallyretarding the speed of the pistons.

Still further objects of the invention are to provide a set of primaryor main pistons operable by suitable driving means and acting uponliquid contained in suitable pressure chambers and a set of secondarypistons which are operable by liquid contained in. said pressurechambers and are adapted to actuate air compressing means and to provideimproved valves for the air compressing chambers.

lVith these and other objects in view, my invention consists in certainnovel features of construction and arrangement of parts,

hereinafter more fully described and claimed, and illustrated in theaccompany in-g; drawings, in

Figure 1 is a front elevation of the air compressor.

Figure 2 is a side elevation of the same.

Figure 3 is a front elevation of the air compressor with parts brokenaway to more clearly illustrate the invention. 7

Figure 4 is avertical longitudinal cross section throughthe .lower endof the air compressor.

Figure 5 is a detail view of the floating member and parts associatedtherewith, showing'the former in a partially rotated position.

Figure 6 is a similar view showing the floating member at "thecompletion of the forward compression stroke and occupying its normalangular position.

Figure is-a vertical cross section taken on line 77 of Figure 1.

Figure 8 is a front elevational view of the floating member and theexternal ring on which the low pressure pistons are mounted.

Figure 9 is a detail longitudinal cross section through the outer end ofone of the low pressure pistons. I

Figure 10 is a horizontal cross section taken on line 10.10 of Figure 1.

Figure 1.1v is a transverse cross section taken on line 1111 of Figure10.

Figure 12 is a vertical transverse cross section taken on line 12-12 ofFigure 10.

Figure 13 is a horizontal cross section taken on line 13-43 of Figure12.

Figure 1 1 is a vertical cross section taken on line 14-14 of Figure 11.

Figure 15 is a horizontal cross section taken on'line 1515 of Figure 12.

Figure 16is a fragmental front elevational view of the pulley showingmeans for conveying the air under pressure to the inlet port of'thedevice.

Figure 17 isv a detail view taken on line 17 17 of Figure 16. i Figure18 is a front elevational view partly in. cross section of a modifiedform of the air compressor.

Referring by numerals to the accompanying drawings; 10 designates acasting or base l es are? sully zdilsjed el tab-satires ing 11 in whichis journaled in bearings 12 a shaft 14. Fixed to the rear end of theshaft is a belt-driven pulley 13 and the forward end of said shaftcarries a crank disk to on which is fixed a crank pin 16. Casting hasformed integral therewith and concentric with shaft 11- a circularflange 10 to which is adapted to be bolted or otherwise secured theannular flange of a circular casing 17. The circumferential wall of cas-17 is provided on the diametrically opposite sides with openings inwhich are reccived the inner ends ct bushings 18. The outer reduced endsof these bushings are seated in suitable openings formed in the lowerends of vertically disposed tubular meniheis 1t) and connect the outeroil chamber 20 of casing 17 with the respective chambers Q1 of membersor columns 19. Bushings i8 and. the lower ends of members 19 arepreferably secured to casing 17 by n'ieans of bolts 22 seated in laterallugs on the lower ends of members 19 and having their threaded endsscrew-seated in casing 17.

Operating in bushings 1S and adapted to enter chambers 21 are primary orhydraulic pistons 24, the inner ends of which are fixed to a ring orstrap 25. Rotatably mounted vithin this ring is a floating member 26having formed in its inner side a slot 27 which is angularly disposedrelative to the axes of pistons 24. Slidably arranged in slot 27 is ablock 28 in which operates crank pin 16 of disk 15. The sides of slot 27are preferably concave in cross section and the slotengaging sides ofblock 28 are convex in order to form a snug lit.

The floating member 26 can be formed in any suitable manner and in thepresent instance consists of two segments held in their relativepositions by means of a circular plate 29 and suitable fastening means30. The outer oil chamber 20 is formed by providing casing 17 with apartition wall 31 which is spaced inwardly from the circumferential walloi? the casing and extends upwardly a suitable distance above pistons2 1. Crank disk 15, ring 25, and parts associated therewith are locatedin the inner oil chamher 32 formed by said wall and are lubricated byoil contained therein.

The upper end of each column or member 19 is provided with a circinarseat designed to receive the reduced end of a piston casing ill. Theenlarged opposite end of each piston casing is provided with an annularseat. for receiving the'outer end of an air cylinder and the inner endsof these cylinders are seated in annular seats 't'orincd in the ends 01a centrally arranged valve casing 36. Operating in each air cylinder 35is a piston 37 and the two pistons are interconnected by a rod 37, whichlatter is slidably mounted. in a hearing formed in valve casing 36.Projecting outwardly from each, an; piston,

37 is a secondary hydraulic piston 38, the diameter of which is smallerin proportion to piston 24.

The end of each secondary piston 38 operates through a bushing '89 andis designed to enter the upper end of the respective oil pressurechamber 21. Bushings 39 are preferably seated in the upper ends ofmembers 19 and project into the reduced ends of piston casings 34. Valvecasing 36 cylinders casings 3 1 and bushings 39 are in axial alignmentwith each other and are held in assembled relation by means of tie rods4:0, the threaded ends of which pass through apertures formed in lugsprojecting laterally from members 19 and receive nuts 41.

Valve casing 86 is divided into two chamhers. one of which is-a highpressure chamher 1% having outlet pipe connections 415 and the other isa low pressure chamber l6 having an inlet pipe connection 4:7. Plates 48are disposed in each end of valve casing 36 and close communicationbetween cylinders and chambers 44 and 46 so that no air can passtherebetween except through inlet openings 49 formed in, said plate andcontrolled by low pressure valves 50 and cylinder outlet openings 51also formed in said plates and controlled by high pressure valves 52.

Each high pressure valve 52 is formed of a comparatively thin metalplate, one end of which is clamped between casing 36 and plate 48 whilethe free end projects within chamber 44 and is provided with asemispherical protuberance which is designed to be seated in andyieldingly close outlet opening 51. Low pressure valves 50 are formedfrom a disk of thin m tal, the inner portion of which is cut or stampedout to provide an inverted U-shaped member 5 1-, the ends of which areunited with the ring portion 54%.

The U shaped portion 54: has formed thereon a valve which is designed tobe seated in and. close the inlet opening 49 of the respective plate 48.These valves open inwardly into the respective cylinders and the legs ofthe U-shaped portion torm re silient means for holding said valves totheir seats in inlet openings 49.

In order to prevent accidental displacementof valve during assembling,casing 36 is provided with outwardly projecting pins 53 which aredesigned to engage apertures suitably located in valve men'ihers 5 Inthe operation of the valves, air is drawn into the respective cylinderduring the expansion stroke of piston 37 through inlet pipe 47 intochamber 46, from which it passes through inlet opening if) to saidcvlinder. Valve 55 is unseated during the t pansion stroke of pistons 37while valve remains seated, and closes outlet opening U on're ml of th dr ction at ra l, of

piston 37, valve is closed and the air contained in this cylinder iscompressed to a definite point whereupon valve 52 opens and permits thecompressed air to escape into chamber 1 1, thence through pipe 415 to asuitable reservoir.

The outer or opposite ends of air cylinders are bridged orinterconnected by a pipe connection 2-35 which acts as a by-pass andbalances the pressure between these ends. Extending upwardly from theupper ends of each member 19 is a pipe or by-pass connection 56 the endsof which are connected by a manually operable valve 57.

In starting the operation of the device, valve 57 is opened so that theoil can pass from one member 19 to the other and become balancedwhereupon valve 57 is closed.

Floating member 26 has anoperative flexible connection with ring 25 bymeans of a leaf spring 58 which is fixed to said member by means of abolt 59 seated in plate 29 and having its slotted end projectingoutwardly and engaging said spring. The threaded end of bolt 59 receiveswashers 60 which are clamped against the spring by means of nuts 61. Theends of springs 58 are arranged on the opposite sides of pins 62, whichlatter are carried by ring 25.

Projecting outwardly from plate 29 are diametrically opposed blocks 64having their sides, facing spring 58, curved and adapted to engage saidspring when floating member 26 is partially rotated in ring 25. Thecurved sides of block 64: gradually engage spring 58 and serve toprevent the excessive rotating movement of floating member 26.

In the operation of the device shaft 14: is driven by pulley 13 causingcrank pin 16 to travel in the direction indicated by the arrow. Crankpin 16 through the medium of block 28 and floating member 26 operatesring 25 so that pistons 24 are reciprocated and alternately enterpressure chambers 21 of the corresponding members 19. These chambers arecompletely filled with oil so that when one of the pistons 24: is forcedinto the respective oil chamber, the pressure created by the displacedoil acts on the corresponding secondary piston 38 causing it to moveinwardly into. a retracted position. Sii'nultaneously with this'action,suc tion is created in the opposite chamber by the withdrawal of theopposite piston 24: thereby permitting the corresponding secondarypiston 38 to enter the upper end of the opposite pressure chamber 21.Second? ary pistons 88 being connected toyair pistons 37, it will bereadily understood that pistons 37 are caused to operate in aircompression chambers of cylinders 35 inunison with the actuation ofpistons 38.

In order to prevent oil from being forced by the pressure in chambers 21along piston a an cylinders ear-e be provided near its inner ,endwithannular groove .65 with which is connected one end of. a pipe 66 and theopposite end of said pipe is connected to the oil chamber 21 on theopposite side. Thus the surplus oil is caused'to flow from groove 6550fthe high pressure side through pipe 66 to the opposite or low pressurechamber 21. Check valve 67 is arranged in each pipe 66 near its point ofconnection with chamber 21 and prevents the back flow 01"- oil throughsaid pipe when the respective chamber 21 is under high pressure.

A pipe connection '68 extends from an annular groove 69 formed in thehead of piston casing 34 and is connected at its lower end to the lowerend of a vertically disposed pipe 70 which is connected near its lowerend to oil chamber 20 by a pipe 71. A check valve 72 interposed in pipe7-1 prevents the flow of oil from said chamber into pipe 70.Pipeconnections 73 are connected at their upper ends to air cylinders 35and their lower ends are connected to pipes 70 at points arranged abovethe level of oil in the outer oil chamber 20. Thus any oil which mayhave found its way in air cylinders 35 is drained through pipes 78 intopipes 70. I

In order to prevent air from being conveyed to the chamber 20, pipes 73are connected to pipes 70 above the level of oilin said chamber and theupper end of pipe 70 is open to the atmosphere preferably being closedby a perforated cap 7 1so that any air entering through pipes 73 will bedis charged through the open upper end of pipe 70. The lower ends ofmembers 19 are closed by plugs 75 screw-seated thereinand screw-lugs .76close openings formed in the side walls of said members in alignmentwith pistons 24. Similar screw-plugs 77 close openings in the upper endsof members 19.

Pistons 24 are provided in their outer ends with longitudinal bores 78,the inner ends of which, when saidpistons occupy retracted positions,communicate with oil chamber 20. The outer end of each bore opens intothe respective pressure chamber 21 and is normally or during thecompression stroke of the piston closed by a spring pressed ball 79 asshown in Figure 9. During the inward or expansion stroke of the piston,ball 79 is unseated and .a limited till stroke of said piston, anannular shoulder 81, formed on said piston, first closes the open end ofsaid circular chamber, and then forces the oil contained therein throughabore 82 formed longitudinally in the inner end of said piston to theinner periphery of ring 25. The outer periphery of floating member 26 isprovided with a circumferentiaily disposed groove or recess 88, the areaof which is preferably equal to the area of piston 2 1. and the oilpasses from bore 82 into said groove and lubricates the inner face ofring A portion of the oil passes from recess 83 through a bore 8% to theconcave faces of slot 27 and the bearing faces of block 28 which latterare provided with suitable recesses 85 for receiving the oil and are ofsubstantially the same areas as the areas of pistons The surplus oil iscollected in the inner chamber 3:? and is partiali discharged or thrownoutwardly by the paddle 86 rormed on the periphery of the rotating crankdisk 15 into the outer oil chamber 20.

In the modified form shown in Figure 18 the oil pressure members 8?converge upwardly and formed integral with the upper ends thereof is anair cylinder casing 88 having air compression chambers 89 at itsopposite ends, each of which is provided with suitable valve means 90.Operating in these chambers are pistons 91 to which are connected highpressure pistons 92. These high pressure pistons operate in highpressure chambers 93, the inner ends of which communicate with pressurechambers in members and their outer ends terminate short of air chambers89. Pistons 92 are interconnected by rod 9% and air compression chambers89 are connected by a by-pass 95. Thus, when low pressure piston 96enters the lower end of member 87, pressure is transmitted through theoil contained therein against the inner end of piston 92 in chambercausing said piston to move outwardly thereby operating piston 91 of theair compression chamber 89. The compressed air is discharged throughoutlet pipe 97 while fresh air is admitted to the inlet pipe 98, bothlocated in the head of each air compression chamber in which are alsolocated valve means 90.

l igures 16 and 17 show the outer end of inlet pipe 17 provided with ascoop 4-7? which terminates adjacent to the inner periphery of a rim 1.8of pulley 13. As the pulley revolves, the air is forced outwardly by theradial fan blades or spokes 13" against the rim 13. This rim has formedintegral therewith inwardly presented circular flanges 13 and 13,respectively, which, together with rim 13 form an air pocket and trapthe air so that it readily enters the inlet pipe 47 through scoop 47 Theheating member 26 pellllits the changing of the angular position of slot27 whereby the speed of pistons 24: is retarded during the compressionstroke in proportion with the increase in pressure or load encounteredby the piston. The curved sides of blocks 64 are designed to cooperatewith the springs 58 not only to prevent excessive rotative movement ofmember 26 but also to form a gradual substantially ri 'id operativeconnection between the feeding means and the piston carrying ring 25after the slot- 27 has assumed its extreme position.

The provision of two sets of hydraulic pistons, one set of which isoperable by the hydraulic pressure created in the respective pressurechambers by the other or primary set, perniits the secondary set to beof smaller cross section relative to the primary set so that saidsecondary pistons receive a longer stroke as compared with the primarypistons. This difference in the operating strokes oi"- the primary andsecondary pistons causes the air compression or low press re pistons tohave a comparatively long b-LlOl-{C and by virtue of the flexibleconnection between shaft 1-l and ring 25, said air compressing pistonsare operable at variable speed, the action of the pistons being retardedapproximately during the last half of the con'ipression stroke.Theuoperation of pistons 24 whereby the latter alternately enter theirrespective chambers 21 produces undulating motion of the liquidcontained therein, which motion or pressure acts upon secondary or longstroke pistons, causing the same to operate in unison with the primarypistons.

Oil passages 82 are designed to deliver oil to the bearing times of theparts involved and serve to not only lulu'ieate said bearing faces butalso to transmit the pressure from pistons to the oil contained inrecesses 83 and and through them the pressure is transmitted to the oilbetween the ring 25 and floating member 26 and block 28, which partsC(Yll'lllllilliCtli'O with and are supplied with oil from the respectiverecesses. Thus the pressure is distributed to the various parts of thefloating member and ring 26 by means of the oil and said operating partsare thereby relieved from undue strains which would result in uneven orexcessive wear of the bearing faces of said parts.

I claim:

1. An air compressor comprising a primary piston, means for actuatingsaid piston, operative connections in said means for automaticallyvarying the speed of said piston during each stroke, a pressure chamberadapted to be wholly tilled with liquid, said liquid being arranged tobe placed under pressure by said piston, a secondary piston operating insaid pressure chamber and adapted to be actuated; by said, liquid,

llll

an air con'ipressionchamber, an air piston operating in said chamber andinterconnected to said secondary piston, andvalves for said aircompression chamber.

2. In an air compressor, a rotatable member, a crank pin carriedthereby, a bearing block for said pin, a ring, a reciprocating pistonfixed thereto, and a floating member arranged in said ring and having apartial rotative movement relative thereto, said floating member beingprovided with an an gularly disposed slot in which is slidably mountedsaid bearing block whereby the speed of the piston is varied by virtueof the partial rotary movement of said floating member.

3. In a device of the class described, a driving means, a crank pinoperable thereby, a bearing block for said pin, a floating mem berhaving a diametrical slot formed therein, said slot being angularlydisposed relative tosaid piston and adapted to slidably receive saidbearing block, and a ring. encircling said floating member and havingsecured thereto one end of said. piston, said floating member beingadapted to partially rotate under the pressure exerted upon it by saidbearing block thus changing the angle of said slot and varying the speedoi said piston.

4. In a device of the class described, a driving means, a crank pinoperable. thereby, a bearing block for said pin, a floating memberhaving a diametrical slot formed therein, said slot beingangularly'disposed relative to said piston and adapted to slidablyreceive said bearing block, a ring encircling said floating member andhaving secured thereto one end of said piston, said floating memberbeing adapted to partially rotate under the pressure exerted upon it bysaid bearing block thus changing the angle of said slot and varying thespeed of said piston, and flexible operative connections between saidring and said floating member.

5. In a device of the class described, a driving means, a c 'ank pin ope"able thereby, a bearing block for said pin, a floating member having adiametrical slot formed therein, said slot being ang ula'rly disposedrelative to said piston and adapted to slidably receive said bearingblock, a ring en circling said floating member and having securedthereto one end of said piston, said floatin member bein ad'a ated to)artia'll rotate under the pressure exerted upon it by said bearingblock thus changing the angle of said slot and varying the speed of saidpiston, and resilient means operatively interposed between said ring andthe floating member and adapted to restore the floating member to itsnormal position.

6; An air compressor "comprising a pair of fluid pressure chambers,means operable at variable speed for placingsaid chambers underpressure, a pair 01 oppositely ,dis posed reciprocating pistons adaptedto be operableby the fluid pressure created in said chambers, aircompression chambers, pistons operating in said chambers and actuated bysaid fluid pressure pistons, and valve means for said air compressionchambers. V

'7. An air compressor comprising a housing, a pair of tubular membersadapted to contain liquid and connected at their lower ends to saidhousing, a pair of oppositely disposed pistons arranged in said housingand adapted to have their outer ends enter the respective tubularmembers, means in said housingfor reciprocating said pistons, tubularcasings fixed to the upper ends oi said tubular members, interconnectedpistons mounted injsaid casings and adapted to enter said tubularmembers and be actuated by the liquid displaced by the first mentionedpistons, air compression chambers located adjacentto said tubularcasings, pistons operating in said'cylinders and actuated by said liquidcontrolled pistons,and valve means arranged between the inner ends ofsaid compression chambers.

8. An air compressor comprising a housing, a pair of tubular membersadapted to be Wholly filled with oil and connected at their lower vendsto said housing, a pair of their outer ends enter the respectivetubulair members and displace the oil contained therein, means in saidhousing for reciproeating said PlSllOIlS, tubular casings fixed to theupper. ends of said tubular members, secondary pistons arranged in saidcasings, and operable by the displaced oil, air compression meansactuated by said secondary pistons, and means, in said primary pistonsfor admitting oil from said tubular members to said housing during thecompression strokes of said pistons,

9. An air compressor comprising a housing, a pair of tubularmeinbersadapted to be Wholly filled With oil and connected at their lower endsto said housing, a pair of oppositely disposed primary pistons arrangedin said housing adapted to have their outerends enter the respectivetubular members and displace the oil contained therein, means in saidhousing for reciprocating said pistons, tubular casings fixed to theupper ends of said tubular members, secondary pistons arranged in saidcasings and operable by thedisplaced oil, aii'rcompre ssion means Iduring the compression strokes of saidpistons, and check valves in saidmeans for closing the passage during the expansion strokes of thepistons.

10. An air compressor comprising a housing, a pair of tubular membersconnected at their lower ends to said housing and adapted to be whollyfilled with oil, a pair of oppositely disposed primary pistons arrangedin said housing and adapted to enter the respective tubular members anddisplace the oil contained therein, means in said housing forreciprocating said pistons, casings fixed to the upper ends of saidtubular members, secondary pistons operating in said casings anddesigned to be actuated by the displaced oil, air compression meansoperated by said secondary pistons, each of said piston casings beingprovided with an annular inwardly presented groove encir cling thepiston, and a pipe connection leading from each of said annular groovesto the tubular member on the opposite side whereby oil which enters saidcasing from the respective tubular member when the latter is under highpressure is collected in said groove and conveyed by said pipeconnection to the opposite or low pressure tubular member.

11. An air compressor comprising a housing, a pair of tubular membersconnected at their lower ends to said housing and de signed to be whollyfilled with oil, a pair of oppositely disposed primary pistons arrangedin said housing and adapted to have their outer ends enter said tubularmembers and displace the oil contained therein, means in said housingfor reciprocating said pistons, tubular casings fixed to the upper endsof said tubular members, secondary pistons mounted in said casings andadapted to enter said tubular members and be actuated by the displacedoil, air compression cylinders, pistons arranged in said cylinders andoperable by said secondary pistons, valve means arranged between theinner ends of said air compression cylinders, and a pipe connectionbetween the outer or dead end of each cylinder and said housing forreturning the oil from the cylinder to the oil chamber in said housin12. An air compressor comprising a housing, a pair of tubular membersconnected at their lower ends to said housing and designed to be whollyfilled with oil, a pair of oppositely disposed primary pistons arrangedin said housing and adapted to have their outer ends enter said tubularmembers and displace the oil contained therein, means in said housingfor reciprocating said pistons, tubular casings fixed to the upper endsof saidtubular members, secondary pistons mounted in said casings andadapted to enter said tubular members and be actuated by the displacedoil, air compression cylinders, pistons arranged in said cylinders andoperable by said secondary istons, valve means arranged between theinner ends of said air compression cylinders, a pipe con nection betweenthe outer or dead end of each cylinder and said housing for returningthe oil from the cylinder to the oil chamber in said housing, and aby-pass connection between the outer ends of said air compressioncylinders.

13. An air compressor comprising a housing, a pair of tubular membersconnected attheir lower ends to said housing and de signed to be whollyfilled with oil, a pair of oppositely disposed primary pistons arrangedin said housing and adapted to have their outer ends enter said tubularmembers and displace the oil contained therein, means in said housingfor reciprocating said pistons, tubular casings fixed to the upper endsof said tubular members, secondary pistons mounted in said casings andadapted to enter said tubular members and be actuated by the displacedoil, air compression cylinders, pistons arranged in saidcylinders andoperable by said secondary pistons, valve means arranged between theinner ends ol said air compression cylinders, and a pipe connectionconnected to each piston casing at a point immediately adjacent to theair cylinder and connected to said housing at a point below the level ofthe oil contained therein.

1 An air compressor comprising a housing, a pair of tubular membersconnected at their lower ends to said housing and designed to be whollyfilled with oil, a pair of oppositely disposed primary pistons arrangedin said housing and adapted to have their outer ends enter said tubularmembers and displace the oil contained therein, means in said housingfor reciprocating said pistons, tubular casings fixed to the upper endsof said tubular members, secondary pistons mounted in said casings andadapted to enter said tubular members and be actuated by the displacedoil, air compression cylinders, pistons arranged in said cylinders andoperable by said secondary pistons, valve means arranged between theinner ends of said air compression cylinders, and a manually controllcdby-pass connection between the upper ends of said tubular members.

15. In an air compressor, a revoluble member, a crank pin carriedthereby, a circular floating member provided with an angularly disposedslot, a block slidably arranged in said slot and forming a bearing forsaid crank pin, a ring loosely arranged on said floating member, andreciprocating pistons carried by said ring.

16. An air compressor comprising driving means, a primary piston, aflexible operative connection therebetween for retarding the speed ofsaid piston, a pressure chamber wholly filled with liquid and having thecompression end of said piston operating therein'whereby he liquidcontained therein receives undulating motion, a secondary piston incommunication with said pressure chamber and adapted to be actuated bythe undulating pressure created in said chamber by said liquid, and aircompressing means operable by said secondary piston.

17. In an air compressor, a housing provided with an oil chamber,actuating means, a ring arranged in said housing, a floating membermovably mounted in said ring and having an angularly disposed slot,ablock connected to said driving means and slidably arranged in saidslot, a piston arranged on said ring and provided with a longitudinallydisposed bore, one end of which communicates with suitable recessesformed in the bearing faces of said floating member and said block, anda bearing for said piston and having a tubular extension with which theopposite end of said bore is adapted to communicate, said tubularextension being adapted to receive oil which is then dis chargedtherefrom under pressure through said bore to said oil "recesses,thereby placing the oil contained between the bearing faces of said ringand said floating member and the block under pressure.

18. In an air compressor, the combination with the inlet port thereof,of a rotating wheel, an inlet pipe connected at one end to said inletport and having its opposite end terminating adjacent to the innerperiphery of said wheel whereby the air impinging on said ring. is drawninto said inlet pipe.

-19. In an air compressor, the combination with thcginlet port'thereof,of a fly wheel, an inlet pipe connected to said inlet port andterminating adjacent to said wheel, a scoop arranged on the endof saidinlet pipe and radially disposed relative to the inner periphery oi saidfly wheel, said fly wheel being provided with inwardly presentedcircular flanges whereby the air centrifugally forced against said ringis forced through said scoop into said inlet pipe.

In testimonywhereof I hereunto aiiix my signature this 13th day of July,1922.

JOHN O. CARREY.

